Telescope-mount.



Patented May 6, |902.

B. A. FISKE.

TELESSDPE MOUNT.

(Application filed Oct. 29, 1901.)

2 sheets-sheet l.`

(No Model.)

- INVENTOR g Bv MAM-1- l" ATTORNEY WITNESSES w@ Patented May 6, |902;

B. A. FISKE.

TELESCDPE MOUNT.

(Application led Oct. 29, 1901.)

igualar/Mun n BRADLEY A. FSK,' OF THE UNITED STATES NAVY.

TELESCPEJVIOUNT.

SPECIFICATIGN forming part of' Letters Patent NO. 699,300, dated May 6, 1902. p

Application filed October 29, 1901. Serial No. 80,418. (No model.)

T0 @ZZ whom t may concern:

Be it known that I, BRADLEY A. FIsKn, of the United States Navy, have invented a new and useful Improvement in Telescope-Mounts for Ships Use,` of which the following is a specification.

The object of the invention' is to enable a' structed asto enable the line of sight to be conveniently kept steady upon the object.

My invention further consists in the various combinations set forth in the claims.

In the accompanying drawings, Figure lis a plan view of the telescope and its carriage. Fig. 2 is a side elevation and section on the line l l of Fig. 2, the lower portion of the supporting-standard being omitted; and Fig. 3 is an end View.

Similar letters of reference indicate like parts.

A represents the telescope,having the usual tube B, containing the object-glass, and the tube C, sliding therein, carrying the eyepiece Y. 'The telescope is detachable audis clamped by the set-screws D between the parts of the supporting ring or band E. Said-band is carried by arms F, which are pivoted at their ends in the standards G. To one of said arms F and outside the pivot thereof is secured a depending lever H, provided with a handle I. The standards G are secured upon thearms J of a carriage which is pivoted so as Vto turn freely in azimuth upon the top of main standard L, which rests on the deck of the vessel and is attached thereto in any suitable way. Said carriage K also has an arm M,which supports clamping-bands N. vVithin said bands, respectively, are vertical guide-tubes O, and between said tubes there is a vertical frame P, carrying two pulleys Q. Vithin the tubes O are counterweights R, which are attached to the free end of the telescope by cords S, passing through pulleys Q. Said cords may l be detachably connected to fixed rings on the telescope-tube B. On the standard L is a fixed gear T, with which engages worm-wheel U on carriage K. Said worm-wheel is rotated bythe hand-Wheel-V and the telescope thus i turned in azimuth.

Extending between the tops of standards .I above the telescope is a bar W, preferably covered with rubber tubing X or other' soft material.

It will be obvious from the foregoing that the telescope A is pivoted at its eyepiece end, while the free end is counterbalanced by the weights R in the tubes O. Hence it will re main in any position in which it may be adjusted in a vertical plane, while, as already stated, it may be directed in a horizontal plane by means of the worm-gear T U. By means of this construction it becomes possible for the iirst time, so far as I know, to handle efficiently a long telescope on shipboard. The reason wh y this has been impracticable hitherto resides mainly in the difficulty of supporting and quickly controlling such an instrument. It is practically impossible for an observer to hold a long telescope steadily to his eye by means of his hands alone, for under themost ordinary conditions of weather the necessary length of the telescope-tube renders it easily deflected by a very moderate side wind, while the unavoidable trembling of the muscles of the observer, increasing as the strain continues, soon renders the instrument useless because of its vibration, andthe movements of the vessel in a seaway are in themselves sufficient to destroy steadiness. It is therefore absolutely necessary for the effectiveuse of any telescope which by its size is difficult tohold properly to the eye to provide some kind of mechanical support which shall make the telescope steady and also quickly movable; but the devising of such'a support is a problem. It must be so constructed as that the eyepiece end of the instrument shall remain relatively fixed with respect to the eye of the observer, or, to put it another way, the construction must besuch as that it will be virtually as easy for him to keep the instrument directed upon the object as to keep his own eye directed thereupon, while simultaneously accommodating himself to the irregular motions of the ves- IOO sel. This l am able to accomplish not only by arranging the telescope in its support so that it will have an easy motion in the vertical and horizontal planes, but by the expedient of pivoting it at the eyepiece end instead of elsewhere.

The term at the eyepiece end as used in the preceding sentence and in the claims means that the axis about which the telescope is elevated or depressed is to be placed in such close proximity to the eyepiece end that the eyepiece end will not have a movement in arc sufficient to disturb to any injurious extent the line of sight of the observer through the telescope upon the object, the eye of the observer remaining stationary and not being raised orlowered. A brief consideration of possible conditions will show the importance of this. Assume the telescope to be placed at one side of the ship, with its longitudinal axis parallel to the plane of the deck to be trained directlj,7 abeam or at right angles to the fore-and-aft axis of the vessel and, for illustration, to be directed upon an object on the horizon. .Then if the ship rolls in direction toward the object it will be necessary for the observer if the telescope .is supported elsewhere than at the point statedas, for example, at its middle-to elevate its objective end and so lower its eyepiece end with reference to the plane of the deck of the vessel in order that he may keep his line of sight upon that object; but in order to preserve his own balance as the ship rolls in the direction stated it is necessary for him to move his body in opposite direction to that of the roll, and therefore his tendency is to carry his eye upward or in the opposite direction to the movement of the eyepiece before stated, or, more briefly, in such circumstances the tendency of movement of the eyepiece of the telescope and of his own eye are in relatively opposite directions. To compensate for this, he must therefore adjustvhis own body not only with reference to the direction of gravity, but with reference to the placing of the telescope-eyepiece, and this he must keep doing constantly and in varying degree, as the movement of the vessel constantly varies. The result is that the maintenance of an accurate line of sight depends upon him rather than upon the instrument. lf, however, the telescope is pivoted at its eyepiece end, as I have described,then this difficulty is removed. It may be objected that even with a telescope thus pivoted it will be difficult for an observer to hold himself sufciently quiet While the ship is rolling or pitching, so as to keep his eye in position before the eyepiece. This difficulty is, however, practically obviated by the employment of the fixed transverse bar W, arranged directly over the eyepiece and at such a distance therefrom as that the observer may rest and brace his forehead against it while he rests his body on the carriage K. The lever H being rigidly attached to the telescope acts also as a brace for him, besides enabling him easily to elevate or depress the instrument. In addition to grasping the handle I in one hand he holds the worm-WheelU in the other. lele thus braces himself by both arms, while pressing his forehead against the cross-bar WV. As a consequence he finds no difculty'in maintaining a sufficiently-firm position, while keeping his line of sight always directed upon the object, despite the motion of the vessel. The mode of holding the telescope as here provided is also such that it cannot be disturbed by a side wind. The carriage K is pivoted at its center of figure, so that the wind has no tendency to rotate it, and the tube Bis received in the frame P and has only just sufficient clearance at its sides to allow it to be freely moved up and down, so that in case of a wind sufficiently strong to deflect laterally the object end of the telescope the only effect would be to move it over a very small fraction of an inch and then into contact with one side 4of the frame. The counterweights R are also to be made of a neat fit within the tubes, and of course all parts of the apparatus are to be assembled so that there will be a minimum of lost motion and vibration.

It may be added that although this apparatus is intended for any use to which it may be found applicable it is especially designed for employment on War vessels, where the great range of modern high-power artillery has for some time demanded means for assisting the sight much more efficient than can be arranged in any apparatus which can be held in the hands of the observer. It is true that some limited advantages have been gained by the use of specially-constructed binoculars in which by the use of prisms and numerous deflections of the visual rayit has become possible to reduce the length of the instrument much below what would be required if the glasses were arranged in straight telescopetubes; but the great difficulty here is the loss of light incident to the many refractions which speedily impose a limit upon the diameter of the object-glass, a disadvantage which does not affect my apparatus, in which a telescope of any reasonable length may be arranged,

l claiml. A telescope and a support therefor, the

said telescope being mounted on a pivot and having its eyepiece in the line of said pivot.

2. The combination of a telescope pivoted for vertical motion and having its eyepiece in the line of its pivot, and a supporting-carriage pivoted for motion in azimuth.

3. A telescope, a carriage therefor, the said telescope being pivoted to said carriage at its eyepiece end and a head-rest on said carriage, disposed above said eyepiece.

4. A telescope, a carriage therefor, the said telescope being pivoted to said carriage at its eyepiece end and means for counterbalancing the free end of said telescope.

5. The combination of the carriage K, standards G thereon, telescope A pivoted at IOS its eyepiece end in said standards and means supported on said carriage for counterbaiancing the free end of said telescope.

6. The combination of the carriage K, standards G thereon, telescope A pivoted at its eyepiece end in said standards, means supported on said carriage for counterbaiancing the free end of said telescope, a lever H for turning said telescope on its pivot, the said counterbalancing means and lever H being connected to said telescope on opposite sides of said pivot.

7. The combination of the carriageA K, standards G thereon, telescope A pivoted at its eyepiece end in said standards, means supported on said carriage for counterbaiancing the free end of said telescope, and a head-rest V supported on said standards G and above said eyepiece.

8. The combination of the carriage K, standards G and tubes O thereon, a telescope A pivoted at its eyepiece end in said standards and counterba1ance-weights connected to said telescope and suspended in said tubes.

9. The combination of a carriage, arms pivoted at one end on said carriage, a telescope A supported by said arms, and means for counterbalancing said telescope.

10. The combination of a carriage, arms pivoted at one end in said carriage, a telescope supported by said arms, and detachably connected thereto, and means for counterbalancing said arms and telescope detachably connected to the end thereof.

11. The combination of the carriage K, standards G thereon, telescope A pivoted at its eyepiece end in said standards, means supported on said carriage for counterbaiancing said telescope, and an arm H for turning said telescope 0n its pivot.

12. In combination with a telescope-mount having a carriage movable about a vertical pivot and two standards on said carriage, a telescope supported on a horizontal pivot between said standards, and having its eyepiece in the line of said horizontal pivot.

BRADLEY A, FISKE.

Witnesses J. A. VAN WAR'I", H. R. MOLLER. 

